The Carotene and Retinol Efficacy Trial (CARET) was a randomized, double-blind, placebo-controlled trial of the cancer prevention efficacy and safety of a daily combination of 30 mg of (3-carotene and 25,000 ID of retinyl palmitate in 18,314 persons at high risk for lung cancer. The trial began recruitment in 1985 and was halted in January 1996, 21 months ahead of schedule, with the twin conclusions of no benefit and substantial evidence of a harmful effect of the intervention on both lung cancer incidence and total mortality. Participants were followed for over nine years post-intervention, with updated lung cancer incidence and cardiovascular disease mortality findings published in 2004. On June 30, 2005, CARET stopped active follow-up of participants. During the active intervention phase of CARET, serum, plasma, whole blood, and lung tissue specimens were collected. These biospecimens make up the CARET biorepository which is the focus of this UMl application. The CARET biorepository is a key tool in studying disease development and progression and is an invaluable legacy of the parent trial and has been open to any investigator with a hypothsis driven project. To date we have provided biospecimens from the repository to investigators which have resulted in 39 peer reviewed publications. Currently there are 29 active projects. In this application we request funds to continue support ofthe CARET biorepository and the associated extensive database, in addition, we will use this opportunity to request funds to extend the CARET database and improve the accessibility of our biorepository to investigators. The specific aims of this application are: 1) Maintain and support the CARET Biorepository and database to contribute to and collaborate in research, 2) Extend the CARET database and online accessibility to include participant use of micronutrient, mineral, and vitamin supplements; baseline laboratory values; and stage at diagnosis of lung, prostate, and colon cancer cases. 3) Extend CARET follow-up with cancers, deaths, and causes of death via public registry searches.